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  A. 
  M. 
  Mayer 
  — 
  On 
  the 
  Flotation 
  of 
  

  

  tension 
  along 
  the 
  lower 
  borders 
  of 
  the 
  two 
  water-surfaces 
  ; 
  one 
  

   of 
  these 
  on 
  the 
  outer 
  side, 
  the 
  other 
  on 
  the 
  inner 
  side 
  of 
  the 
  

   axis 
  of 
  the 
  ring. 
  Thus 
  while 
  we 
  cannot 
  deduce 
  a 
  reliable 
  

   measure 
  of 
  the 
  surface 
  tension 
  from 
  a 
  knowledge 
  of 
  W 
  and 
  P 
  

   in 
  the 
  case 
  of 
  the 
  disk, 
  we 
  have 
  conditions 
  quite 
  favorable 
  to 
  

   that 
  measure 
  in 
  the 
  case 
  of 
  the 
  floating 
  ring. 
  

  

  If 
  a 
  floating 
  ring, 
  fig. 
  4, 
  formed 
  of 
  wire 
  of 
  l 
  mm 
  in 
  diameter, 
  

  

  Fig. 
  4. 
  

  

  be 
  gradually 
  loaded 
  by 
  pouring 
  fine 
  sand 
  into 
  the 
  cup 
  carried 
  

   by 
  the 
  ring, 
  it 
  sinks 
  deeper 
  and 
  deeper 
  into 
  the 
  depressed 
  sur- 
  

   face 
  of 
  the 
  water 
  till 
  it 
  has 
  reached 
  a 
  depth 
  of 
  0*503 
  cm 
  , 
  when 
  

   it 
  suddenly 
  breaks 
  through 
  the 
  surface 
  and 
  sinks. 
  

  

  Fig. 
  5. 
  

  

  As 
  the 
  ring 
  descends 
  in 
  the 
  depression 
  in 
  the 
  water, 
  the 
  lat- 
  

   ler 
  incloses 
  more 
  and 
  more 
  of 
  the 
  ring 
  till 
  the 
  opposite 
  surfaces 
  

   of 
  the 
  depression 
  have 
  approached 
  to 
  T 
  V 
  mm 
  as 
  shown 
  in 
  fig. 
  5, 
  

  

  